Why does a cup of human blood milk have a fatal temptation to people? What kind of twisted psychology would be crazy about it, even willing to kill one after another? Extraordinary killers and crimes beyond common sense require extraordinary detectives. Fang Mu (played by Li Yifeng), a young and energetic criminal psychology top student, tried to help, but was dragged into it; Tai Wei (played by Liao Fan), a beast-style criminal police captain with extraordinary skills, hated evil, but found it difficult to get out of the quagmire in his heart. The two joined forces and became a perfect partner! A contest of skills and a competition of minds unfolded...